Early on, industry manufactured both short- and long-length door latches. The short-length latch resulted in the door handle axle being about 60 mm from the door's edge. The long-length latch resulted in the door handle axle being about 70 mm from the door's edge.
Use of short- and long-length latches resulted in many doors existing in the marketplace having perforations, either for the long-length or the short-length latch. The existence of two distinct types of doors required services of door latches to stock both short and long latches. Services had to stock long latches to service doors previously perforated for long latches, and services had to stock short latches for doors previously perforated for short latches. In addition, manufacturers had to make both short and long door latches to fulfill the needs of their customers. It became very expensive to stock and manufacture both long and short door latches.
To solve the problem, industry developed a single latch capable of being adapted to fit either a door previously perforated for a short latch or previously perforated for a long latch. Some adaptable latches adapt by providing a linkage between an eccentric and two possible pre-established positions on a bolt tail. The design complicates the latch. The linkage requires provisions to provide for door axle rotation at either of the two linkage positions on the bolt tail.
Other devices provide for the adaptation within the bolt case. Some of these devices produce a helical movement between the extreme positions of 60 mm and 70 mm. Some of the devices produce the movement by a right side-up or upside-down U-shaped movement between the positions.
Accordingly, the present invention seeks to improve upon previous adaptable latches by providing a bolt head having a bolt head catch, and by providing a bolt tail having a bolt tail appendage. The bolt tail appendage has a bolt tail appendage first catch and a bolt tail appendage second catch. The bolt tail appendage first catch and the bolt tail appendage second catch are longitudinally spaced from each other along a longitudinal length of the latch. The bolt head catch locks with either the appendage first catch or the appendage second catch.
The invention further provides advantages by providing a bolt case extension having a bolt case extension first catch and a bolt case extension second catch. The case extension first catch and the case extension second catch are longitudinally spaced apart along the longitudinal length of the latch. A resilient catch coupled to the bolt case locks with either the bolt case extension first catch or the bolt case extension second catch.
The invention provides still a further advantage by providing a bolt tail protrusion which has a pressed position. The protrusion, when in the pressed position, unlocks the resilient catch from the case extension first catch or case extension second catch. In addition, it unlocks said bolt head catch from the bolt tail appendage first catch or the bolt tail appendage second catch.
The invention further improves upon prior latches by providing a spring-loaded lug which co-acts with both said bolt tail appendage and said resilient catch to provide for a simultaneous unlocking of said bolt head catch from said appendage and said resilient catch from said case extension.